抄録
The whole-rock chemistries of the mafic rocks in the Moho Transition Zone, Fizh Massif, the Oman ophiolite have been analyzed by X-ray fluorescence spectrometry. The mafic rocks were classified into three texture types based on their microstructures: weakly deformed gabbro, moderately deformed gabbro and ultramylonites. There is no systematic variation of the whole-rock chemistries among the three texture types. The ultramylonites show various chemistries, although they consist mostly of very fine-grained matrix with minor relatively coarser porphyroclasts. It may suggest the effect of fluid-rock interaction during ductile shearing in the Moho Transition Zone or variation of the mafic rock chemical compositions.